The two "hub" academic medical centers of the New York Presbyterian (NYP) Healthcare System - Columbia University Medical Center (CUMC) and Weill-Cornell Medical Center (WCMC) - have helped lead the way in developing promising new treatments for neurological emergencies. These include the application of therapeutic hypothermia after cardiac arrest, the Merci'clot retriever for acute ischemic stroke, midazolam infusion for refractory status epilepticus, and clinical trials evaluating neuroprotective agents for acute stroke, thrombolytic therapy for intraventricular hemorrhage, and ultra-early hemostatic therapy with recombinant activated factor VII for intracerebral hemorrhage. Columbia University Medical Center is one of seven NIH SPOTRIAS research centers;central to this effort is the multidisciplinary SPEED team, led by emergency medicine, which continuously evaluates acute stroke care at both of our hubs and has driven substantial reductions in door-to-needle times for IV t-PA. These cooperative efforts between emergency medicine and neurology are further supported by an established infrastructure that facilitates collaboration throughout the NYP Healthcare System, including a Stroke Center Clinical Council, Emergency Medicine System Forum, and one of the largest independent ambulance systems in the United States. The overall goal of the present application is to build on our existing expertise in clinical research, our history of collaboration between emergency medicine and the clinical neurosciences at our two hub hospitals, and our track record of well-coordinated efforts throughout the NYP Healthcare System, in order to develop a 10-hospital New York-Presbyterian NETT Consortium for conducting neuroemergency clinical trials. Collectively these 10 emergency departments treat an ethnically diverse patient population that exceeds one half million patients per year. We will pursue the following specific aims: (1) Establish a leadership group of four co-principal investigators representing emergency medicine and neurology from both of our hub hospitals, supported by two half-time NETT project coordinators;(2) Organize emergency medicine and neurology co-investigators at 8 additional NYP network hospitals, each supported by a part- time NETT coordinators;(3) Create a 24-hour physician coverage system to provide clinical and research support to our regional emergency departments;(4) Develop a new EMS-triggered pre-hospital warning system to reduce the time needed to trigger clinical trial procedures;(5) Formally link the NYP Stroke Center Clinical Council, NYP Emergency Medicine System Forum, and the SPOTRIAS Speed Team;and (6) Develop unified time-based performance standards for managing neuroemergency patients, and implement an internet-based surveillance system to provide continuous quality improvement (CQI) data for our sites.